Background: This survey was intended to investigate prevalence and severity of early childhood caries (ECC) in a sample of children in Southern Italy and to identify factors that may be related to this condition. Methods: The study was designed as a cross-sectional survey. The study population (children aged 36–71 months) attending thirteen kindergartens was randomly selected through a two-stage cluster sampling procedure. Parents/guardians of all eligible children were invited to participate filling out a structured self-administered questionnaire, and after having returned the informed consent form an oral examination of the child was performed at school. The questionnaire included information on: socio-demographics about parents/guardians and child, pregnancy and newborn characteristics, oral hygiene habits of child, eating habits particularly on consumption of sweets, access to dental services, and infant feeding practices. The WHO caries diagnostic criteria for deciduous decayed, missing and filled teeth (dmft) and surfaces (dmfs) were used to record ECC and severe-ECC (S-ECC). Univariate and multiple logistic regression analyses were conducted to evaluate statistical associations of social demographics, infant feeding practices, oral hygiene habits, and access to dental services to ECC, S-ECC, dmft and dmfs. Results: 515 children participated in the study. 19% had experienced ECC, and 2.7% severe-ECC (S-ECC), with a mean dmft and dmfs scores of 0.51 and 0.99, respectively. Mean dmft was 2.68 in ECC subjects, and 6.86 in S-ECC subjects. Statistical analysis showed that prevalence of ECC significantly increased with age (OR = 1.95; 95% CI = 1.3-2.91) and duration of breastfeeding (OR = 1.26; 95% CI = 1.01-1.57), whereas it was significantly lower in children of more educated mothers (OR = 0.64; 95% CI = 0.42-0.96), and higher in those who had been visited by a dentist in the previous year (OR = 3.29; 95% CI = 1.72-6.33). Conclusions: Results of our study demonstrate that even in Western countries ECC and S-ECC represent a significant burden in preschool children, particularly in those disadvantaged, and that most of the known modifiable associated factors regarding feeding practices and oral hygiene are still very spread in the population.